Pushing the boundaries of green construction

25 September 2020
At LafargeHolcim, we are reinventing how the world builds to push the boundaries of green construction, with circular and low-carbon solutions.
 

Carbon-neutral construction in Europe and beyond

In Germany we have passed the next frontier of green construction with the delivery of EcoPact Zero, our carbon-neutral concrete. This revolutionary green product was poured to create floor slabs for two extensions covering 650 square meters for the foundations of a park’s center for biological diversity.

The building is expected to be finalized in the spring of 2021.

"More than 90% of our concretes are already made with CO2-reduced cement, so our carbon-neutral concrete, Holcim EcoPact Zero, is a natural next step," says Thorsten Hahn, CEO of Holcim Germany. "And it is only a step. We will continue to advance sustainable construction through innovation, digitalization and the continued support of our industry and customers."

Building on its success in Germany and Switzerland, ECOPact is being deployed worldwide. Everywhere ECOPact is offered, it will represent at least 30% lower carbon emissions than standard concrete in its markets. ECOPact has already been sold in the Washington, DC and Boston metropolitan areas and it continues to be rolled out across North America.

ECOPact Zero -- meaning 100% carbon-neutral concrete -- is achieved mainly through process innovations, with the remaining unavoidable carbon emissions eliminated through carbon offsets. The next frontier is to deliver 100% carbon neutrality without any offsets required. Our innovation centers worldwide are actively working on this, with 50% of our patents in this area today.

Mainstreaming circular construction with Susteno

Holcim Switzerland introduced Susteno 3R, the first and only cement in Europe that uses 20% of fine mixed rubble from demolished buildings as a component. Roughly a third of landfills across Europe contain construction waste, and globally construction waste is projected to grow to 2.2 billion tons by 2025. In Switzerland, there are roughly 16 million tons each year, of which around 85% are recycled.

The challenge is that the fine fractions of mixed demolition rubble are difficult to use, which is why they are mostly landfilled. Holcim Switzerland developed Susteno with Eberhard, a pioneer in recycling construction materials. Together they looked for a sustainable solution for mixed demolition rubble that would otherwise go to landfill.

For one, they had to research the right quality parameters for the mixed demolition rubble and develop the process to produce a stable quality. For another, a new cement had to be designed based on components that hadn’t been mixed before. This required top technical experts and meticulous work in the laboratory with extensive testing. Martin Preisig, Eberhard Bau AG remembers: “The collaboration with Holcim during the research and development of these products was great, as we complemented each other very well and worked as partners.”

The new cement also benefited from the revision of the Swiss building code (SIA Code of Practice 2049) that allowed new types of mineral components in cements which was key to give stakeholders the certainty that the new type of cement is safe, well regulated, and meets all quality standards.

Wolfgang Herrmann, an engineer with WHP, Ingenieure in Swiss city of Basel, is excited about the prospects: “Sustainable construction must use sustainable materials while ensuring the durability of buildings. Susteno closes the construction cycle and with Evopact I am happy to rely on a sustainable concrete that conserves resources and saves landfill space.”

At a global level, LafargeHolcim is taking circularity much farther. The company recycled 48 million tons of waste last year, which makes it the second global leader in waste solutions worldwide, contributing to cleaner cities while preserving earth’s finite resources. The Company has committed to doubling its recycling rate to 100 million tons by 2030.

Accelerating the transition to green infrastructure

The transition to green infrastructure is more urgent than ever. More than two billion people are projected to move into cities by 2050 and more than half the infrastructure to support that growth still needs to be built.

Partnerships are the key to accelerating this transition. A case in point is LafargeHolcim’s partnership with GE Renewable Energy and COBOD to co-develop wind turbines with optimized 3D printed concrete bases, reaching record heights up to 200 meters. “It’s a stepping stone into the next generation of wind plants,” says Paul Veers, Chief Engineer at the National Wind Technology Center and a senior research fellow at the US National Renewable Energy.

Traditionally built in steel or precast concrete, wind turbine towers have typically been limited to a height of under 100 meters, as the width of the base cannot exceed the 4.5-meter diameter that can be transported by road, without excessive additional costs.

Building on the industry-leading expertise of each partner, this collaboration aims to accelerate the access and use of renewable energy worldwide. Printing a variable height base directly on-site with 3D-printed concrete technology will enable the construction of towers up to 150 to 200 meters tall. Typically, a 5 MW turbine at 80 meters generates, yearly, 15.1 GWh. In comparison, the same turbine at 160 meters would generate 20.2 GWh, or more than 33% extra power.

We are also providing high-performance materials to build dams for hydropower and protecting shores for coastal resilience.